Shingle with improved blow-off resistance

ABSTRACT

A wind-resistant shingle and a method of making it is provided in which the rear surface of the shingle is provided with an attached reinforcement layer, which resists upwardly wind-applied bending torque when the shingle is installed on a roof, such that the failure of the shingle when it is bent beyond its elastic limit, is resisted until the shingle has absorbed a high percentage of applied torque.

This is a continuation of prior application Ser. No. 10/288,747 filedNov. 6, 2002, now U.S. Pat. No. 6,758,019.

BACKGROUND OF THE INVENTION

In the manufacture of shingles, it has been known that when shingles aresubjected to strong winds, the winds can engage the lower edges or tabportions of the shingles, and bend them upwardly.

On occasion, under strong winds, the tabs can bend upwardly in amountssufficient that the inherent, internal resistance to substantial bendingand perhaps cracking, can be overcome, in that the mat that is formedinternally of the shingle, and the asphaltic material on the surfaces ofthe shingle, may not be sufficient to withstand certain wind conditions.

Various approaches have been made to resist shingle failure via crackingand the like, not all with substantial success.

For example, strips of adhesive material along lower ends of tabs ofshingles have been applied, which, when subjected to hot weatherconditions, softens an amount sufficient that such adhesive will adhereto the next-subjacent shingle on a roof, eventually harden andthereafter resist upward deflection of shingle tabs under severe windconditions. However, such adhesive sometimes dries out, offering reducedadhesion. In other cases, the wind conditions can exist during hightemperature conditions when such adhesive located under tabs remainssoft, and thus the adhesive does not function in its intended manner.

Other approaches have resorted to thickening the mat and/or asphalticmaterial, to offer internal resistance to bending, but nonetheless,failures due to wind-related bending of tabs of shingles continue toexist.

SUMMARY OF INVENTION

The present invention is directed toward providing a wind-resistantshingle, wherein a separate, exterior reinforcement layer is providedoutside the rear surface of the shingle, with such layer comprising amaterial that is not coated or covered by any thick layer of asphalt orthe like, such that the material that comprise the reinforcement assistin absorbing the torque that is applied to the shingle tabs byupwardly-lifting winds.

Accordingly, it is an object of this invention to provide a novelshingle having a wind-resistant layer on the lower surface of theshingle, that comprises a reinforcing material.

It is a further object of the invention to accomplish the above objects,wherein the reinforcement layer comprises a scrim material that includeslifting-torque absorbing strands.

It is another object of this invention to accomplish the above object,wherein the scrim extends into the tab portion of the shingle.

It is a further object of this invention to accomplish the objectsabove, wherein the shingle absorbs a high percentage of the liftingtorque that is applied to the shingle, under conditions in which the tabedge of the shingle is lifted as much as or more than 45°.

It is a further object of this invention to provide a method of makingshingles in accordance with the objects set forth above.

Other objects and advantages of the present invention will be readilyunderstood upon a reading of the following brief descriptions of thedrawing figures, detailed descriptions of the preferred embodiments andthe appended claims.

BRIEF DESCRIPTIONS OF THE DRAWING FIGURES

FIG. 1 is a rear elevational view of a shingle made in accordance withthe prior art.

FIG. 2 is an illustration like that of FIG. 1, but wherein the shingleis shown to have a reinforcement layer applied to the rear surfacethereof, in accordance with the present invention.

FIG. 2A is a fragmentary sectional view of the shingle of FIG. 2, takenalong the line 2A—2A of FIG. 2.

FIG. 3 is an illustration like that of FIG. 2, but wherein thereinforcement layer extends farther into the tab portion of the shinglethan in the embodiment of FIG. 2.

FIG. 4 is a side view of the shingle of this invention shown resistingtorque applied to the tab portion of the shingle under a wind-liftingforce that bends the shingle upwardly at approximately 45°.

FIG. 5 is a graph showing an example of the absorption of wind-liftingtorque upon bending a particular weight of shingle through variousangular degrees and the improvement of providing a reinforcementmaterial in accordance with this invention under the same liftingconditions.

FIG. 6 is a view similar to that of FIG. 5, for a somewhat differentweight of shingle, and a different weight of mat for the shingle.

FIG. 7 is an illustration similar to that of FIGS. 5 and 6 for adifferently constructed shingle.

FIG. 8 is a graph similar to that of FIG. 7, for a shingle having awider reinforcement layer.

DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

Referring now to the drawings in detail, reference is first made to FIG.1, wherein a prior art shingle is illustrated as comprising a shinglegenerally designated by the numeral 10, constructed as a mat ofpreferably fiberglass mesh, having asphalt, or some other form ofbitumen material impregnated therein, and forming layers on each surfacethereof, with a granular material on each exposed surface. On the upperexposed surface, will be granules of a size desired to resist sun andother weather conditions, and on the opposite, or undersurface 11, therewill be preferably smaller granules of a mica or like material, forexample. The shingle 10 has a headlap portion 12 and a tab portion 13,having slotted openings 14 dividing the tab portion 13 into a number ofdiscrete tabs 15. On the undersurface 11 there is provided preferably asheet of release paper or tape 16, which is removed when the shingle isinstalled on a roof, but which, for stacking shingles for shipmentprevents the shingle from sticking to a subjacent shingle in the stack,which subjacent shingle has a similarly located strip of adhesivematerial, such as more bitumen, extending longitudinally from edge 17 toedge 18, on the front surface of the subjacent shingle.

The basic shingle of FIG. 1 may be made in accordance with the teachingsof U.S. Pat. Nos. 6,092,345, 6,145,265, or 5,822,943, the completedisclosures of all of which are herein incorporated by reference.

With specific reference to FIG. 2, it will be seen that a shingle 20 ispresented, having a rear surface 21, with a release strip 26 runningfrom left to right across the lower end of a headlap portion 22, betweenedges 27 and 28, and with the tab portion 23 of the shingle 20comprising a plurality of tabs 25 separated by vertical, spaced apartslots 24.

As shown in FIG. 2A, the shingle of FIG. 2 is comprised of a base layerof mat 5, with coatings of asphaltic material 6 on each side thereof,with large granules 7 on the front side, adhered to the asphalticmaterial 6, and with small granules 8 on the rear side adhered to theasphaltic material 6.

A nailing zone exists on the front surface of the shingle 20, generallylocated above the release tape or strip 26, running between edges 27, 28above the slots 24. Essentially, the shingle 20 is similar to that ofthe shingle 10 of FIG. 1, except that a 2½ inch wide preferablyfiberglass reinforcement layer that may comprise a scrim layer 29 isadded on the rear 21 of the shingle 20, across the upper end of the tabportion 23, and across the lower end of the headlap portion 22, coveringthe area shown in FIG. 2, as well as the area disposed beneath therelease strip 26, along the lower end of the headlap portion 22 betweenedges 27 and 28. During the construction of the shingle of FIG. 2, thereinforcement layer 29 is thus applied before the release tape 26 isapplied.

The reinforcement layer 29 will probably be a fiberglass scrim and willpreferably be a woven construction, involving woven strands disposed atright angles to each other, with a preferred density of, for examplenine strands in the vertical direction and nine strands in thehorizontal direction per square inch of scrim (9×9 per in²).

With reference to FIG. 3, it will be seen that a shingle 30, much likethe shingle 20, is provided, having a rear surface 31, having a headlapportion 32 and tab portion 33, with the tab portion comprising aplurality of tabs 35 separated by slotted openings 34, with a releasestrip 36 extending between left and right edges 37 and 38, and with ascrim 39 located beneath the release strip 36 as with respect to theembodiment of FIG. 2, but extending downwardly farther into the tabs 35,as shown, in that the scrim 39 is essentially 6 inches wide, runningfrom the upper edge of the release strip 36, into the tabs, as shown.

It will be apparent that other lengths of scrim 29, 39, will beappropriate depending upon the desired resistance to bending under windconditions, as will be addressed hereinafter.

As shown in FIGS. 2, 3 and 4, the scrim layers 29, 39 and 46 each havefront and rear surfaces, with the front surfaces adhered to the rearsurfaces of the shingle and, will not be coated with a bitumen or otherasphaltic material on their rear surfaces, nor will they have granulesapplied thereto, such that the filaments of the scrim 29, 39, especiallythose extending vertically as shown in FIGS. 2 and 3, can resist bendingand resist failure in the form of the likelihood of forming horizontalcracks across the upper end of the tab portion of the shingle, when theshingle is bent upwardly within its elastic limit under forces appliedby winds.

The scrim may have a density other than the 9×9 per in.² addressedabove, such as but not limited to 8×8 per in.² or 7×7 per in.², and maybe of various compositions other than fiberglass, such as polyester,polypropylene and/or nylon. In lieu of a scrim, the reinforcement layers29, 39 may comprise thin fabric, plastic film, paper, parchment, foil orthe like, either embedded in the asphaltic layer on the rear of theshingle or adhered to the rear of the shingle by an additionalpost-applied thin layer of asphaltic or non-asphaltic adhesive. Thereinforcement layer 29, 39, will be adhered to the rear surface 21, 31of the shingles of this invention, by means of any suitable adhesive,such as a bitumen or the like, or any other adhesive.

With reference now to FIG. 4, it will be seen that a roof 40 isfragmentally illustrated, having a shingle 41 fastened thereto by meansof a nail, staple, 42 or the like. When wind forces occur in the generaldirection indicated by the arrow 43 in FIG. 4, such that they tend tobend the tab portion 44 of the shingle upwardly to an angle “a”, asshown by the dotted arrow 45, the scrim 46 applied to the undersurfaceof the shingle 41 will tend to resist upward bending of the shingle tabportion 44, largely because of the resistance to such bending that isprovided by the reinforcement layer 29, 39 as shown in FIGS. 2 and 3which will resist stretching and thereby inhibit bending.

It will be understood that up to some level of force applied by wind inthe direction 43, the shingle tab portion 44 will bend within itselastic limit in accordance with Hook's law. In this regard, any givenweight of shingle, under any particular conditions, will have its ownmodulus of elasticity, which is a measure of the stiffness or rigidityof the shingle, generally arrived at on an empirical basis, and withinwhich the shingle will return to its original, flat condition when theforce of wind is removed.

Reference will now be made to the graphs of FIGS. 5–8, forrepresentative benefits achieved by using a scrim applied to shingles inthe manner discussed above, for various weights of shingles havingdifferent mats, and under the same temperature conditions, forcomparison purposes.

With reference to FIG. 5, it will be seen that a shingle version isidentified as version 3, with its control identified as version 3C, eachbeing a 250 lb, shingle, in weight per square (1 square equals enoughshingles to cover 100 ft² of roof) and with 2.5 lb. mat. (in weight per100 square feet of mat). In each case, the samples were tested at 30° F.The ordinate or vertical measure in the graph is the percent of theapplied force or load that is absorbed by the shingle at a given degreeof angular bend, as shown in degrees on the abscissa or horizontal lineof the chart, under a fixed torque applied to the shingle tab portion,of 6.0 inch-lbs. It will be seen that for the control shingle of FIG. 5,failure, or inelastic bending to the point that the shingle does notreturn to its original, flat condition when the force of wind isremoved, occurred at about 40° of angular bend, with failure beingdefined as a crack or permanent bend as distinguished from a bend withinthe elastic limit. However, for the shingle having a scrim of 2½ inchesin width, as shown in FIG. 2, it will be seen that in FIG. 5 thatshingle with the scrim remained within its elastic limit up to about 60°of angular bend, prior to failure. It will thus be seen that thespecimen graphed in FIG. 5 having a scrim applied thereto absorbed about75% of the torque load applied thereto, for a bend of the tab portion ofthe shingle of about 60°, before failure.

Referring now to FIG. 6, wherein a version 4 was matched against acontrol version 4C, for a 235 lb. weight of shingle having a 2.6 lb.mat, again at 30°, the control version absorbed about 60% of the torquethat was applied, up to about 40° of angular bend, whereas the specimengraphed in FIG. 6 having a 2 1/2 inch wide scrim applied theretoabsorbed about 77% of the applied torque load, when subjected to a bendof 60°, before failure.

Referring now to FIG. 7, wherein yet another shingle 5 was testedagainst a control shingle 5C, with the shingle graphed in FIG. 7, likethat of FIG. 6 also being a 235 lb. weight per stack, but having a 2.5lb. mat, and likewise having a 2½ inch wide scrim, it will be seen that,whereas the control version absorbed only about 55% of the appliedtorque at about a 40° bend, the version with the scrim applied theretoabsorbed about 70% of the applied load, when bent about 70°. Thus, theeffect of a slightly thinner mat was noted for a shingle with scrimapplied thereto.

With reference now to FIG. 8, it will be seen that shingle versions 6and control shingles 6C were also shown as comprising a 235 lb. shingleby weight, and a 2½ lb. mat, but wherein, unlike the similar specimenindicated for FIG. 7, the specimen graphed in FIG. 8 had a 6 inch widescrim applied thereto. It will be seen that the control version of FIG.8 tested similarly to that of the control version of FIG. 7, and thatthe version with the 6 inch scrim applied thereto likewise testedsimilarly to that of the scrim-applied version of FIG. 7.

It will thus be seen that the bending tests, performed with aTinius-Olsen Flexibility Tester to apply the force bending the shingletab portions 44 in the direction of the arrow 45 of FIG. 4 all show thatthe specimens with scrim reinforcement embedded on their rear sidesexhibit improved resistance to failure upon bending, and thus arecapable of maintaining and carrying applied stress due to bending tomuch higher degrees than shingle specimens without the scrim. Thus,shingles with the scrim applied thereto in accordance with thisinvention provide improved resistance to damage due to wind uplift.

It will apparent from the forgoing that various modifications may bemade in the details of construction, as well as with the use of shinglesof this invention, all within the spirit and scope of the invention asdefined in the appended claims.

1. A wind-resistant shingle having front and rear surfaces, a widthdefined by upper and lower edges and a length defined by right and leftedges, comprising: (a) a base layer of mat having front and rearsurfaces; (b) a coating of asphaltic material on both front and rearsurfaces of the mat presenting corresponding front and rear asphalticmaterial surfaces; (c) coatings of granular material on the asphalticmaterial on both front and rear surfaces of the asphaltic material; (d)a longitudinal fastening zone between right and left shingle edges,generally intermediate said upper and lower edges; (e) a generallylongitudinal wind-resistant layer having front and rear surfaces, withits front surface adhered to said rear surface of said shingle, andextending at least substantially between right and left edges of theshingle; (f) said wind-resistant layer extending at least partiallylower than the fastening zone, toward the lower edge of the shingle; and(g) said wind-resistant layer comprising a scrim of crossing strands ofreinforcing material with the rear surface of the scrim being uncoatedwith asphaltic material.
 2. The shingle of claim 1, wherein the shinglecomprises an upper headlap portion and a lower tab portion; with the tabportion comprising a plurality of tabs spaced by slots that extendupward toward the headlap portion from the lower edge; with thefastening zone being generally located above the tab portion.
 3. Theshingle of claim 1, wherein the width of the scrim is approximately 2½inches wide.
 4. The shingle of claim 1, wherein the width of the scrimis approximately 6 inches wide.
 5. The shingle of claim 2, wherein ascrim extends for a width of approximately 1 inch above the upper endsof the slots.
 6. The shingle of claim 5, wherein the width of the scrimis approximately 2½ inches wide.
 7. The shingle of claim 5, wherein thewidth of the scrim is approximately 6 inches wide.
 8. The shingle ofclaim 1, wherein the scrim comprises a cross-hatched plurality ofstrands of at least 9×9 per inch².
 9. The shingle of claim 1, whereinthe scrim is of a strand density, thickness and strength such that theshingle absorbs 80% of 6 inch-lbs. of lifting torque at a 50° angle oflift of the lower edge of the shingle relative to the upper end of theshingle, without shingle failure.
 10. The shingle of claim 1, whereinthe scrim is of a strand density, thickness and strength such that theshingle absorbs 70% of 6 inch-lbs. of lifting torque at a 60° angle oflift of the lower edge of the shingle relative to the upper end of theshingle, without shingle failure.
 11. The shingle of claim 1, whereinthe scrim is exposed and uncovered on the rear surface of the shingle.12. The shingle of claim 1, wherein the scrim comprises means forincreasing the amount of applied lifting load that the shingle willabsorb, under bending conditions, within the elastic limit of theshingle, prior to failure.